/* 公共样式 */

* {
    margin: 0;
    /* 去掉内边距 */
    padding: 0;
    box-sizing: border-box;
}

html, body {
    height: 100%;
    background-image: url(../img/backimg.jpg);
    /* 不平铺 */
    background-repeat: no-repeat;
    background-position: center center;
    background-size: cover;
}

.nav {
    height: 50px;
    background-color: rgba(148, 179, 225, 0.5);
    color: aliceblue;
    line-height: 50px;
    padding-left: 20px;

    font-size: 18px;
    font-weight: 100;
}

.container {
    /* 占除了导航框以外的空间 */
    width: 100%;
    height: calc(100% - 50px);

    display: flex;
    flex-direction: column;
    /* 水平居中 */
    justify-content: center;
    /* 垂直居中 */
    align-items: center;

}